Previous studies on feeder use in group-housed pregnant sows focused on dynamic groups and protected electronic sow feeders (ESF). This study observed 60 pregnant sows, 1st to 8th parity - housed from Day 29 of pregnancy to 1 week before parturition in stable groups of 20 animals, 1 Fitmix feeder per group. Data from 25 nonconsecutive 24-hr feeding cycles showed sows making several visits to the feeder. Literature on conventional ESF indicated shorter daily feeder occupation. Daily feeder occupation per sow decreased over time (p < .001). The study observed maximum feeder activity in the hours following the start of each feeding cycle. During the experiment, there was a relatively stable, quickly established, and maintained feeder order (W > 0.80, p < .001). This highly correlated with dominance rank (rs = 0.80, p < .001). High-ranking sows fed earlier and made as many - but longer - visits as low-ranking sows; thus, they occupied the feeder more time every day (p < .01). Although optimization of the feeder efficiency may take several weeks, Fitmix seems an efficient feeding system for medium-size, stable groups of sows.
Chapinal, N., Ruiz-de-la-Torre, J. L., Cerisuelo, A., Baucells, M. D., Gasa, J., & Manteca, X. (2008). Feeder use patterns in group-housed pregnant sows fed with an unprotected electronic sow feeder (Fitmix). Journal of Applied Animal Welfare Science, 11, 319-336. https://doi.org/10.1080/10888700802329939